Art of increasing fading resistance of dyestuffs



Patented Nov. 26, 1940 more! STATES PATENT. ori ice Incorporated, Chicago,

West Virginia No Drawing.

9 Claims.

This invention relates to the art of increasing the fade resistance of dyestuffs. More, particu-' larly, it relates to material having, uniformly distributed on its surface, a substance which will retard the fading of dyestuffs.

A preferred embodiment of this invention comprises a copy sheet suitable for use in duplicating processes, having associated therewith a substance which will retard the fading of dyestuffs l0 usedin duplicating inks.

I have discovered that. aerogels have the property of retarding the fading of dyestuffs, and particularly the water and alcohol soluble dye- V stuffs commonly used'ln duplicating inks. The aerogel which I prefer to use is a silica a'erogel.

The preparation of aerogels and the description of their properties is given in a Engineering Chemistry, Vol. 126, page 658 (1934) and also in U. S. Patent to Kistler, No. 2,093,454,,

issued September 21, 1937. From these publicaof the solid component of the gel as it actually exists before treatment and. di'fiering only in that the liquid medium is displaced by a vapor or gas.

In the pra tice of my invention, I may associate the aer gel in various manner with a substance on which the dyestufi is to be applied. a I may incorporate the aerogel uniformly in the substance so that the aerogel is also uniformly dis-.

tributed on the surface. I may also coat the surface of the substance with any type of coating solution,containing aerogel. The aerogel may be associated with various materials to which a dye may be applied, including textiles and paper.

- My invention is-particularly applicable to the preparation of copy sheets suitable for use in duplicating processes. As an example of this application of the invention, the following is given: One part of silica aerogel and five parts of water are ground together, to a thick paste. This paste is applied tosheets of paper which are used as copy sheets in practicing the hectograph process of duplication or in practicing a process wherein the copy sheets are pressed against master sheets to duplicate data thereon, the ink I or carbon on the master sheets being moistened as with a solvent for the ink or carbon. 3

article by S. S. Kistler and A. C. Caldwell, In ustrial and,

111., a corporation of Application February 7,1938, Serial N0. 189,171

It was found that the design reproduced on the aero'gel coated copy sheet was highly resistant to fading in light. For example, seven and one-half hours exposure to'intense ultra-violet light caused no appreciable,fading,whl1e a design on untreated 5' copy paper faded completely under identical conditions.

While I have shown and described certain-embodiments of my invention, it is to be under-- stood that it is capable of many modifications. 10 Changes, therefore, may be made without departing from the spirit and scope of the invention as described in the appended claims; in which it is my intention to claim all novelty inherent'in my invention as broadly as possible, in view of the 15' prior art. V

I claim:

l. A copy paper adapted for usein a transfer process and. designed. to receive andretain color impressions of increased fastness to light'by contact with a configuration of an aqueous or alcohol soluble dye susceptibleto fading in light, comprising a sheet of copy paper having a silica aerogel uniformly distributed over, the contact surface, said aerogel being adapted, to interact with a water or alcohol soluble dye to produce an improved dye having an increased fastness to light.-.

2. Paper having an ae'rog'el uniformly distrib-. uted. on its surface, and, a' design on said surface 80 formed from an aqueous or alcohol soluble dye which is susceptible to fading in light, said aerogel being adapted to interact with the water or alcohol soluble dye to produce'an improved dye having increased fastn'ess to light. 85

3. The method of making transfercopies conv taining a design which is highly resistant to fading inlight, comprising applying a copy sheet containing aerogel on its surface to a surface having a design formed thereon from a water or 40 alcohol soluble dye and thereby transferring a portion of the dye to said copy sheet to form a design thereon, whereby the dye and aerogel coact to render the dye on the copy sheet resistant to fading in light. 45

4. The method of making transfer copies containing a design which is highly resistant to .f'ading in light, comprising applying a copy sheet containing 'silica aerogel on its surface to a surface having a design formed thereon from awater 50 or alcohol soluble dye and thereby transferring a portion of the dye to said copy sheet'to form, a design thereon, whereby the dye and silica aerogel coact'to render the dye on the copy sheet uniformly distributed on a surface thereof, and

a water or alcohol soluble dyestufl which is susceptible to fading in sunlight on said surface adapted to interact with said aerogel whereby increased resistance of the dye to fading in sunlight is attained.- A e 6. A; fabric having an aerogel uniformly disa interact with said aerogel whereby increased resistance of the dye to fading in sunlight is attained. a

7. The method of increasing the fade resistance of water and alcoholi soluble. dyes in the form of designs, characters or the like carried by an 5. article of manufacture having an aerosol article of manufacture which comprises applyingthe dyestufl' to the article having an aerogel uniformly distributed over the contact surface thereof.

8. The method of increasing the fade resistance of water and alcohol soluble dyes in the form of designs, characters orthe like carried by .a fabric which comprises applyfiig the 'dyestuif to the fabric having an aerogel uniformly distributed paper having an. aerogel uniformly distributed l5 overthe contact surface thereof.

JOHAN BJORKSTEN. 

